Security is an increasingly important requirement for many applications, not only software applications, but also when involving physical objects.
For example, a network of devices may have multiple devices, each connected to a system socket. The network configuration may be set by a professional installer, and it may then be desired to ensure that changes are not made to the network without the knowledge or approval of the professional installer or system maintainer. An example is the professional lighting domain. In such a system, it may be desirable to prevent someone inserting, removing or changing a lamp or sensor in a luminaire socket without notice. There can be a variety of risks, such as:
the lighting properties in a room no longer comply with regulations or agreed health conditions for people working in the room;
safety regulations for installing objects in a building may be violated. This can be a large issue for calibrated sensors or other objects;
there can be undesired tampering with the inserted object or its replacement, such as added eavesdropping facilities (e.g., stealth audio or video recording).
Objects of various types can be installed in sockets of various types. Applications, regulations and risks in healthcare or lifestyle domains may also depend on increased control over the plugging in of correct objects to sockets. These objects may be electronic devices, physical objects (such as keys or tokens) or they may be cables attached to other devices or objects.
It is known for a socket to read an identifier of a device which is plugged in to the socket, either to identify the specific device or to recognize the type of device. However, this does not detect unplugging and plugging in of the same device, particularly if there is no power supplied to the device during this time.
There is therefore a need for a system which can detect connection and disconnection of a plug to a socket so that actions can be authenticated.